Revert "ANDROID: cpu/hotplug: rebuild sched domains immediately"

This reverts commit 1d3a64fbd2.

CPU Pause causes major merge conflicts with the 5.11 scheduler changes
(migrate-disable specifically), so lets revert Pause temporarily as it
is not needed urgently in android-mainline.

Signed-off-by: Quentin Perret <qperret@google.com>
Change-Id: I201898fe111d5da25c82b0f6a7b32cd0b1d6f237

include/linux/cpuset.h

@@ -160,8 +160,6 @@ static inline void set_mems_allowed(nodemask_t nodemask)
 	task_unlock(current);
 }
 
-extern void cpuset_hotplug_workfn(struct work_struct *work);
-
 #else /* !CONFIG_CPUSETS */
 
 static inline bool cpusets_enabled(void) { return false; }
@@ -277,8 +275,6 @@ static inline bool read_mems_allowed_retry(unsigned int seq)
 	return false;
 }
 
-static inline void cpuset_hotplug_workfn(struct work_struct *work) {}
-
 #endif /* !CONFIG_CPUSETS */
 
 #endif /* _LINUX_CPUSET_H */

kernel/cgroup/cpuset.c

@@ -342,9 +342,9 @@ static DEFINE_SPINLOCK(callback_lock);
 static struct workqueue_struct *cpuset_migrate_mm_wq;
 
 /*
- * CPU / memory hotplug is handled asynchronously
- * for hotplug, synchronously for resume_cpus
+ * CPU / memory hotplug is handled asynchronously.
  */
+static void cpuset_hotplug_workfn(struct work_struct *work);
 static DECLARE_WORK(cpuset_hotplug_work, cpuset_hotplug_workfn);
 
 static DECLARE_WAIT_QUEUE_HEAD(cpuset_attach_wq);
@@ -3136,7 +3136,7 @@ update_tasks:
  * Note that CPU offlining during suspend is ignored.  We don't modify
  * cpusets across suspend/resume cycles at all.
  */
-void cpuset_hotplug_workfn(struct work_struct *work)
+static void cpuset_hotplug_workfn(struct work_struct *work)
 {
 	static cpumask_t new_cpus;
 	static nodemask_t new_mems;

kernel/cpu.c

@@ -33,7 +33,6 @@
 #include <linux/slab.h>
 #include <linux/percpu-rwsem.h>
 #include <uapi/linux/sched/types.h>
-#include <linux/cpuset.h>
 
 #include <trace/events/power.h>
 #define CREATE_TRACE_POINTS
@@ -1258,15 +1257,6 @@ int resume_cpus(struct cpumask *cpus)
 	if (cpumask_empty(cpus))
 		goto err_cpu_maps_update;
 
-	for_each_cpu(cpu, cpus)
-		set_cpu_active(cpu, true);
-
-	/* Lazy Resume.  Build domains immediately instead of scheduling
-	 * a workqueue.  This is so that the cpu can pull load when
-	 * sent a load balancing kick.
-	 */
-	cpuset_hotplug_workfn(NULL);
-
 	cpus_write_lock();
 
 	cpuhp_tasks_frozen = 0;